I recently had an irrigation system installed in my yard which has mature trees. Coincidentally, I also had an arborist come out the same day to give a price quote on pruning some trees. The arborist looked at the "lines" that were made in the soil to install the underground plastic pipes for the irrigation system. I am not sure how deep the pipes are in the soil.

The arborist told me to forget about the pruning, and strongly recommended getting some sort of nutrients for the trees (2) that should slow the growth for 3-5 years. Slowing the growth is supposed to help in saving the tree since the irrigation lines cuts some of the upper roots of the tree. The cost of the nutrients are $400 total for both trees.

Should I get the nutrients for the trees? The trees are a pin oak and a sugar maple, and I line in Northern Illinois. It is hard for me to believe that much damage to the roots occurred. I asked the irrigation company if it should be a concern, an of course they laughed.

Thanks for any responses.

DeeTee

12-02-2007 03:23 PM

I'm not going to second guess an arborist so I'll just say what I would do if I were facing the same situation in my yard. Some of this is of no use to you since it's done, but for others who might be entering the same waters in the future it might help out. It's never a good idea to damage roots on any kind of tree that you want to keep. Many trees like Siberian Elm will take a lickin and keep on growing, others don't handle it as well. How close the damage is to the trunk can be telling. While trees take the bulk of their nutrients and water up at the dripline, those large roots in next to the trunk are the highways those nutrients travel through. If those have been cut not only could you see one half of the tree die but you could also have a danger of the tree tipping over in a big wind. Irrigation companies that don't have plant care operations often are not very sensitive to the plight of the plants. So if the roots are damaged close to the trunk I don't think I'd do anything but make sure the trees get enough water and then hope for the best. If the roots that were cut are closer to the dripline of the tree then I'd do some root feeding during the winter using a root stimulant product like B1 and deliver it using one of those injector feeders that hooks to the hose, and of course make sure to follow other good cultural practices like cleaning up debris and leaves beneath the tree and making sure it has ample water.

timber

12-02-2007 05:38 PM

Kyle, I'm an arborist from Northeast, IN. Both those trees have a pretty extensive root system. They can easily handle a little bit of root pruning. The Pin Oak is one of the few oaks that grows relatively quickly due to having a more fibrous root system than some of its relatives. The Sugar Maple can also handle the root pruning as long as it didn't get to close to the trunk. The more fibrous a root system, the more root damage it can handle. DeeTee supplied you with some good advice, the B1 will stimulate root hair production for quicker recovery. It wouldn't be a bad idea to inject a little iron into the Pin Oak. There nortorious for getting iron deficiencies. That's if you decide to do a little fertilization. $200-400 is realistic for deep root fertilization or micro-injection by a pro, ask the man what products he wants to use and whats in them. If you guys had a pretty severe drought like we did this past year, I would highly recommend some fertilization but with a low nitrogen level. If there fairly mature trees I wouldn't worry to much. Let us know how it goes.

Kyle

12-05-2007 07:29 PM

Thanks

Thanks for the replies. It was hard to believe that the irrigation system could cause so much damage that required the treatments. We just had had some sort of bio pack treatment done on the pin oak to treat for cholorosis (sp?). It is hard to believe a little injection could cost so much. Anyway, thank again for the replies.